Answer of FAQ

How do I record OpenGL and 3D applications? (with hardware accelerated performance)

How to succeed:

Please use the OpenGL-capable mode of DemoRecorder. ( see below for instructions )

It records the main desktop ( a selectable rectangular area of it, to be more exact )
and it works well with hardware-accelerated OpenGL.

Although this feature is not yet officially released it works quite well and it
is already contained in the normal install package.
Some of my customers already use this mode in a production environment.

If you need help with this mode or if you experience problems with it,
please tell me by email and I will help you.

Example

Here is one example recorded with that mode and exported to avi format:

(this is a recording of the game "glmaze" which is an OpenGL application and a good test-case for OpenGL recording.)

Prerequisites

Currently, this recording mode requires the X-Server to be configured
for 24bit TrueColor.
(Some Linux distributions use 16-bit TrueColor as the default and that won't work.
If the X-Server config does not meet the required 24-bit TrueColor then
DemoRecorder will only record the initial frame but no frames thereafter,
so you'll get a still image instead of a video.)

You can check your X-Server config by entering
the following command into a shell window:

xdpyinfo

...and looking at the output:
Here are the things to look for in the output of "xdpyinfo"
( [...] indicates omitted parts, highlighted stuff
indicates relevant info ):

Exporting

When exporting to FLV and then viewing it in the Flashplayer of your webbrowser (which has to be done through a webserver) please note that the Flash player ( at least under Linux) has some performance problems and is therefore dropping frames if a moving 3D scene is played back. So the Flash player cannot keep pace with the performance that DemoRecorder is capable at recording.

So, for active 3D scenes I recommend the AVI or MPEG format because players for these formats are usually optimized for the case of each part of each frame being different from the pervious frame.
For AVI and MPEG please use a high output-bitrate such as 6000 or even a bit higher.

Sound

For recording sound, please activate your microphone in the mixer-tool of your Linux distribution and please select a recording volume which gives good use of the dynamic range of the A/D converter of your sound card.
The GUI ( the small tuerquois rectangle ) also contains a reclevel meter. A good recording volume is achieved if the white bar in the reclevel meter
is more than 2/3 full if sound is present. If the bar turns partly of fully red, this means that overdrive occurs which is an indication
that the recording volume is too high.

Preview Playback

The GUI of the OpenGL/Animation-mode does not yet provide a preview playback button but you can use
standard demorec for playback. For doing that please start demorec with the resolution of your video, e.g.,